GB2541205A - A steam generator - Google Patents

Abstract

A steam generator 10 for a steam cleaner comprises a housing 12 having a fluid inlet 14, a fluid outlet 16, a fluid flow passage (20a, 20b, fig 5) extending therebetween, wherein the housing 10 further includes a further opening 24 and a further passage (26, fig 5) extending therefrom, wherein at least a portion of the further passage (26, fig 5) forms at least a part of the fluid flow passage (20a, 20b, fig 5), and wherein the opening 24 is closable with a blocking member 30. Also disclosed is steam generator for a steam cleaner wherein the fluid inlet 14, the fluid outlet 16 and the fluid flow passage (20a, 20b, fig 5) lie substantially within a first plane (A, fig 4) and a heating element (40, fig 4) which has a first side portion (42, fig 3) and a second side portion (44, fig 3) and a connecting portion (46, fig 2) extending therebetween, wherein the first side portion (42, fig 3) lies substantially within a second plane (B, fig 4) positioned to one side of the first plane (A, fig 4), and has at least a curved portion (47, fig 3), wherein the second side portion (44, fig 3) lies substantially within a third plane (C, fig 3) positioned to an opposite side of the first plane (A, fig 3) to the second plane (44, fig 3), and has at least a curved portion (48, fig 3). The side portions can be U-shaped.

Description

Title: A steam generator Description of Invention

This invention relates to a steam generator, particularly a steam generator for a steam cleaner.

Steam cleaners are well known in household cleaning. Steam cleaners are able to lift away dirt without using harsh chemicals, which could make an environment (such as a house) unsuitable for children to operate in safely (for example, it could be dangerous for a child to play on a floor if chemical residue is still on the floor after cleaning).

Typically, a steam cleaner includes a water reservoir, a steam generator, and a cleaning head, all of which are fluidly connected. In use, water flows into the steam generator, from the reservoir, via a pump or under gravity. Water enters the steam generator so that it can be heated to produce steam, and the steam exits the steam generator. The steam is then directed to a floor head, so that it can be used to clean a floor or surface.

Typically, the steam generator includes a diecast body, a heating element, and a water conduit. In some known steam generators, an inlet is located at a “top” part of the body and an outlet is located at a “bottom” part of the body, and the water conduit extends between, to provide a straight flow path for the water to pass through. The heating element is generally U-shaped and positioned within the body, and is offset, so that it sits to one side of the water conduit.

Known steam generators are relatively large. Additionally, the heating elements are inefficient because they are required to heat a large amount of material.

According to a third aspect of the present invention, we provide a steam generator for a steam cleaner including a housing having a fluid inlet and a fluid outlet and a fluid flow passage extending therebetween, wherein the housing further includes a further opening and a further passage extending therefrom, wherein at least a portion of the further passage forms at least a part of the fluid flow passage, and wherein the opening is closable with a blocking member.

According to a fourth aspect of the present invention, we provide a steam generator for a steam cleaner including a housing having a fluid inlet and a fluid outlet and a fluid flow passage extending therebetween, wherein the fluid inlet, the fluid outlet and the fluid flow passage lie substantially within a first plane, and a heating element which has a first side portion and a second side portion and a connecting portion extending therebetween, wherein the first side portion lies substantially within a second plane positioned to one side of the first plane, and has at least a curved portion, wherein the second side portion lies substantially within a third plane positioned to an opposite side of the first plane to the second plane, and has at least a curved portion.

According to a fifth aspect of the present invention, we provide a heating element for a steam cleaner including a first side portion, a second side portion and a connecting portion extending therebetween, wherein the first and second side portions both lie substantially within respective first and second planes, and wherein the first and second side portions are substantially U-shaped.

Further features of the various aspects of the present invention are set out in the claims attached hereto.

Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings, of which:

Figure 1 is a view of a steam generator according to an embodiment of the invention;

Figure 2 is a partially exploded view of a steam generator according to an embodiment of the invention;

Figure 3 is a view of parts of a steam generator according to an embodiment of the invention;

Figure 4 is a view of parts of a steam generator according to an embodiment of the invention;

Figure 5 is a cross-sectional view of a steam generator according to an embodiment of the invention;

Figure 6 is a cross-sectional view of a steam generator according to an embodiment of the invention;

Figure 7 is a plan cross-sectional view of a steam generator according to an embodiment of the invention.

With reference to the figures, a steam generator 10 for a steam cleaner is shown. The features of the steam generator are described with reference to a “normal” orientation shown in the figures. It should be appreciated that the orientation of the steam generator 10 need not be the upright “normal” orientation shown in the figures in order to perform its function. For example, a “top” part may be used to describe the relative position of a part, but it should be appreciated that this in relation to the orientation shown and should not be construed narrowly.

The steam generator 10 includes a housing 12 having a fluid inlet 14 (hereinafter referred to as the inlet 14), a fluid outlet 16 (hereinafter referred to as the outlet 16), and a fluid flow passage 20. The steam generator further includes a heating element 40 (described in detail below).

The housing 12 is generally cuboid in shape and each “side” of the housing 12 is a generally flat surface. The top surface 12a includes a raised portion 22 which extends across the housing 12 at one end, which is also generally flat on a top part. The top surface 12a also includes a further opening 24 (described in more detail below). The housing 12 further includes two substantially parallel ridges 25a,b which extend from the bottom surface 12b along the direction of a longest dimension 27 of the housing 12. The inlet 14 is positioned below the outlet 16; both are on a side 12c of the housing 12.

It should be appreciated that the housing 12 need not be cuboidal in shape to perform its function. For example, the housing could be cylindrical, etc. The housing 12 is made of solid material. Preferably, the housing 12 is made from metal (e.g. die cast metal). The metal may be Aluminium, although other suitable alternatives could be used.

The inlet 14 does not need to be below the outlet 16; their positions could be swapped without affecting the function of the steam generator. It should also be appreciated that the inlet 14 and the outlet 16 may lie on different sides of the housing 12. For example, the inlet 14 may be positioned on the side 12c and the outlet 16 on the bottom 12b or top 12a.

In the depicted example, the side 12c lies in one plane, and as such both the inlet 14 and the outlet 16 also lie in that plane. The term “side” should not limit the scope of the application to a single plane. It is contemplated that a “side” could include many facets that lie in more than one plane and are oriented at obtuse angles to one another, and that a “side” could be curved.

The inlet 14 and the outlet 16 have respective connectors 15, 17. The connectors allow the steam generator 10 to be connected to the other working components of a steam cleaner (not shown). In other words, the inlet connector 15 is, in use, fluidly connected to a water reservoir (not shown) and the outlet connector 17 is, in use, fluidly connected to a cleaning head (not shown). Each of the connectors 15,17 has a respective threaded portion 18,19 which is screwed into a correspondingly threaded portion (not shown) extending into the housing 12.

The fluid flow passage 20 fluidly connects the inlet 14 to the outlet 16. The fluid flow passage 20 is substantially circular in cross-section. However, the fluid flow passage 20 could have a variety of cross-sectional shapes, such as, oval, square or rectangular, etc. It should be appreciated that the fluid flow passage 20 may include some irregularities in shape (i.e. it may not be exactly circular, oval, etc.) as a result of tolerances in manufacture (i.e. drilling machinery tolerance, etc.).

In use, the fluid (e.g. water) enters the steam generator 10 via the inlet 14 in a first direction X and exits the steam generator 10 via the outlet 16 in a second (different) direction Y. The first and second directions X, Y are substantially opposite one another. This configuration allows the steam generator to be of a compact design.

The inlet 14 and the outlet 16 and the fluid flow passage 20 define a flow path. The length of the flow path between the inlet 14 and the outlet 16 is longer than the longest dimension 27 of the housing 12. Again, this provides effective heat transfer whilst maintaining a compact design.

The fluid flow passage 20 includes first, second and third passage portions 20a, 20b, 26. The first passage portion 20a extends into the housing 12 from the inlet 14 and the second passage portion 20b extends into the housing 12 from the outlet 16. The first and second passage portions 20a,b are substantially straight and extend substantially horizontally (when the steam cleaner is in its normal orientation). The first and second passage portions 20a,b are substantially parallel with one another.

The third passage portion 26 is formed from a further passage that extends from the further opening 24 on the top 12a of the housing 12. The further passage 26 is substantially straight and extends downwards from the further opening 24. The further passage 26 extends to connect the first and second passage portions 20a,b, and is located at an opposite end of the housing 12 to the inlet 14 and outlet 16. Hence, the third passage portion/further passage 26 extends substantially transverse (in this example, perpendicular) to the first and second passage portions 20a,b.

The opening 24 is closable by a removable blocking member 30. This allows the further passage 26 to be closed, so that in use, the fluid enters the inlet 14, flows through a part of the further passage 26 which connects the first and second passage portions 20a,b, and exits through the outlet 16. In this example, the blocking member 30 has a threaded portion 34 which cooperates with a correspondingly threaded portion extending from the further opening 24 into the housing 12.

It should be appreciated that the first and second passage portions 20a,b do not need to be parallel to one another. Alternatively, the first and second passage portions 20a,b could be inclined to each another and/or each passage portion 20a,b could include curved sections. The third passage portion/further passage 26 may not be perpendicular to the first and second passage portion 20a,b and/or could include one or more curved sections.

The fluid flow passage 20 as a whole includes at least two corners 33a,b which are substantially right-angled. This is as a result of the manufacturing process because the first and second passage portions 20a,20b and the further passage 26 are each individually drilled out from the housing 12. It is simpler and lower cost to drill straight passages, which results in sharp corners rather than curved passages. It should be appreciated that the passage portions 20a,b and further passage 26 may not be drilled. In which case, the fluid flow passage 20 may include one or more curved sections (i.e. the fluid flow passage 20 may not include right-angled corners) connecting the passage portions 20a,b together.

The inlet 14, the outlet 16, and the fluid flow passage 20 all lie substantially within a first plane A (the cross-sectional plane as used in figure 5).

In some embodiments, the inlet 14 may be smaller in cross-sectional area than the outlet 16. This is advantageous because when water is heated, to steam, it expands. Having different cross-sectional areas allows the pressure to remain more stable than if the inlet 14 and the outlet 16 were the same size. Likewise, the first passage portion 20a may have a smaller cross-sectional area than the second passage portion 20b, for the same reason.

The fluid flow passage 20 may also include at least one (but preferably a plurality of) radially inwardly extending rib(s) (not shown). The ribs increase the total surface area of the fluid flow passage 20, and therefore improve the efficiency of heat transfer to the fluid flowing through the passage 20.

As mentioned above, the steam generator 10 also includes a heating element 40 which is advantageously shaped to provide a compact design. The heating element 40 has a first side portion 42 and a second side portion 44 and a connecting portion 46 extending therebetween. Parts of the heating element 40 lie on both sides of the fluid flow passage 20.

The first side portion 42 lies substantially within a second plane B positioned to one side of the first plane A. The first side portion 42 has at least one curved portion 47 which lies within the second plane B.

The second side portion 44 lies substantially within a third plane C positioned to an opposite side of the first plane A. The second side portion 44 has at least one curved portion 48 which lies substantially within the third plane C. In other words, planes B and C are located on opposing sides of the first plane A.

The connecting portion 46 lies substantially within a fourth plane D. The fourth plane D is substantially transverse to the first, second and third planes A, B, C. More preferably, the fourth plane D is generally perpendicular to the first, second and third planes A, B, C.

In the described example and the figures (particularly figure 4), the first, second, third and fourth planes A,B,C,D intersect a generally central axis of the fluid flow passage 20, first and second side portions 42, 44 and the connecting portion 46, respectively. However, it should be appreciated that the planes A,B,C,D may intersect different parts of the fluid flow passage 20, first and second side portions 42, 44 and connecting portion 46, respectively. Additionally, by “lying substantially within a plane” we mean that the generally central axis of each respective component part lies in the plane (i.e. an axis through the centre of the fluid flow passage 20 all lies substantially in the first plane A).

The first and second side portions 42, 44 are substantially the same shape. The shape of the first side portion 42 is described below. It should be appreciated that the second side portion 44 has the same features (but are not given separate reference numbers). The first side portion is substantially U-shaped. There are upper and lower straight sections 42b,42d which are substantially parallel with one another and are connected together by the curved portion 47. The curved portion 47 of the first side portion 42 forms the “bend” of the U-shape. The overall shape of the first side portion 42 is illustrated particularly by figure 6 (a cross-sectional view of plane B and shows the general configuration of the first side portion 42).

The connecting portion 46 also has a portion that is substantially U-shaped. The connecting portion 46 has left and right side sections 46c,d which are connected with a second curved portion 46e. The second curved portion 46e forms the “bend” of the U-shape. The general shape of the connecting portion 46 is illustrated by figure 7 (a plan cross-sectional view). It should be appreciated that the side portions 42, 44 and/or the connecting portion 46 could be other shapes (e.g. an S-shape) and still perform the same function.

The first, second and third planes A, B, C are substantially parallel with one another. Therefore, the first and second side portions 42, 44 of the heating element 40 and the fluid flow passage 20 are all substantially parallel with one another. However, it should be appreciated that the first, second and third planes A, B, C do not need to be parallel with one another (and hence the side portions 42, 44 and the fluid flow passage 20 need not be parallel). For example, the first and second side portions 42, 44 could be inclined at an angle to one another.

Each of the first and second side portions 42, 44 has a terminal connector 50a,b at one end, to connect to an electrical supply (not shown). The heating element 40 is substantially symmetrical about the first plane A. In other words, each side of the heating element 40 is a mirror image of the opposing side.

At least a part of the first and second side portions 42,44 are substantially parallel to at least a portion of the fluid flow passage 20. More specifically, the upper and lower straight sections 42b,42d (no references given for the second side portion 44) of the first and second side portions 42,44 lie alongside, and are parallel with, the first and second passage portions 20b,20a, respectively.

An advantage of the steam generator 10 is that the housing 12 is smaller than prior steam generators. Additionally, the efficiency of the steam generator 10 is improved relative to known designs because the heating element 40 surrounds and lies closer to more of the fluid flow passage 20.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims (31)

1. A steam generator for a steam cleaner including: a housing having a fluid inlet and a fluid outlet and a fluid flow passage extending therebetween, wherein the housing further includes a further opening and a further passage extending therefrom, wherein at least a portion of the further passage forms at least a part of the fluid flow passage, and wherein the opening is closable with a blocking member.

2. A steam generator according to claim 1 wherein fluid enters the fluid inlet in a first direction and exits the fluid outlet in a second direction.

3. A steam generator according to claim 2 wherein the second direction is substantially opposite to the first direction.

4. A steam generator according to any of the preceding claims wherein the fluid inlet and the fluid outlet are both positioned on a first side of the housing.

5. A steam generator according to any of the preceding claims wherein axes of the fluid inlet, fluid outlet and fluid flow passage lie substantially in the same plane.

6. A steam generator according to any of the preceding claims wherein the fluid flow passage has first, second and third passage portions, and the first and second passage portions extend from/to the fluid inlet and fluid outlet respectively.

7. A steam generator according to claim 6 wherein the first and second passage portions are substantially parallel to one another.

8. A steam generator according to claims 6 or 7 wherein the third passage portion is substantially transverse to the first and/or second passage portions.

9. A steam generator according to claims 6 to 8, wherein the further passage is substantially transverse to the first and/or second passage portions.

10. A steam generator according to any of the preceding claims wherein the fluid flow passage includes at least two substantially perpendicular turns.

11. A steam generator according to any of the preceding claims, wherein the blocking member is removable.

12. A steam generator according to claim 11 wherein the blocking member includes a threaded portion which cooperates with a correspondingly threaded portion in the passage which extends from the further opening in the housing.

13. A steam generator according to any of the preceding claims wherein the fluid inlet is smaller in cross-sectional area than the fluid outlet.

14. A steam generator according to any of the preceding claims wherein the fluid flow passage includes at least one inwardly extending rib for improving heat transfer to the fluid.

15. A steam generator for a steam cleaner including: a housing having a fluid inlet and a fluid outlet and a fluid flow passage extending therebetween, wherein the fluid inlet, the fluid outlet and the fluid flow passage lie substantially within a first plane, and a heating element which has a first side portion and a second side portion and a connecting portion extending therebetween, wherein the first side portion lies substantially within a second plane positioned to one side of the first plane, and has at least a curved portion, wherein the second side portion lies substantially within a third plane positioned to an opposite side of the first plane to the second plane, and has at least a curved portion.

16. A steam generator according to claim 15 wherein the first and second planes are substantially parallel and/or the second and third planes are substantially parallel.

17. A steam generator according to claims 15 or 16 wherein the first side portion and/or the second portion of the heating element is/are substantially U-shaped.

18. A steam generator according to claims 15 to 17 wherein a section of the connecting portion is substantially U-shaped.

19. A steam generator according to claims 15 to 18 wherein a section of the connecting portion lies substantially within a fourth plane, which fourth plane is substantiallytransverse to the first plane and/or the second plane and/or the third plane

20. A steam generator according to claim 19 wherein the fourth plane is substantially perpendicular to the first plane and/or the second plane and/or the third plane.

21. A steam generator according to claims 15 to 20 wherein each of the first and second side portions of the heating element has a terminal connector at one end to connect to an electrical supply.

22. A steam generator according to claims 15 to 21 wherein the first and second sides portions of the heating element are substantially identical, preferably mirror images of one another.

23. A steam generator according to claims 15 to 22 wherein the heating element is substantially symmetrical about the first plane.

24. A steam generator according to claims 15 to 23 wherein at least a part of the first and/or second side portions is/are substantially parallel to at least a portion of the fluid inlet and/or fluid outlet.

25. A heating element for a steam cleaner including a first side portion, a second side portion and a connecting portion extending therebetween, wherein the first and second side portions both lie substantially within respective first and second planes, and wherein the first and second side portions are substantially U-shaped.

26. A heating element according to claim 25 which includes any feature or combination of features of the heating element defined in claims 15 to 24.

27. A steam generator including a heating element according to claims 25 or 26.

28. A steam generator according to any of claims 1 to 14 in combination with any of claims 15 to 24.

29. A steam cleaner including a steam generator according to any of claims 1 to 24.

30. A steam generator substantially as described herein and/or as shown in the accompanying drawings.

31. Any novel feature or novel combination of features substantially as described herein and/or as shown in the accompanying drawings.